Question

The average weight of 8 persons increases by 2.5 kg when a new person comes in place of one of them weighing 65 kg. What might be the weight of the new person?

A. 76 Kg

B. 85 Kg

C. 76.5 Kg

D. Data inadequate

Answer 1

Hint: In order to solve this problem we need to obtain the increased weight in total and then calculate the weight of the new person with the help of the weight of the removed person. Doing this will solve your problem.

Complete step-by-step answer:

$ \Rightarrow $ Total number of people whose average weight is calculated is 8.

$ \Rightarrow $ Increased in average weight is 2.5 kg  (given)

$ \Rightarrow $ Then the total weight increased when a new person is added in place of person whose weight is 65kg is 8×2.5kg = 20kg

$ \Rightarrow $ Weight of replaced person  is 65kg

$ \Rightarrow $ Then weight of new person is (65+20)kg = 85kg

Hence, the answer is 85 kg.

So, the correct option is B.

Note: Whenever you face such types of problems never try to assume variables and make an equation of average it would make the solution more and more complicated. Use the average weight increased smartly as done above and calculate the asked term. Proceeding like this will solve your problem.